Surgical end effectors with clamping assemblies configured to increase jaw aperture ranges

ABSTRACT

An end effector for use with a surgical instrument. The end effector includes first and second jaws that are pivotally coupled to each other for pivotal travel about a pivot axis between open and closed positions by a dynamic clamping assembly that is selectively movable between a starting position and an ending position relative to the first and second jaws. At least a portion of the dynamic clamping assembly extends proximally beyond the pivot axis when in the starting position to facilitate improved jaw apertures.

BACKGROUND

The present invention relates to surgical instruments and, in variousarrangements, to surgical stapling and cutting instruments and staplecartridges for use therewith that are designed to staple and cut tissue.

BRIEF DESCRIPTION OF THE DRAWINGS

Various features of the embodiments described herein, together withadvantages thereof, may be understood in accordance with the followingdescription taken in conjunction with the accompanying drawings asfollows:

FIG. 1 is a perspective view of an electromechanical surgical system;

FIG. 2 is a perspective view of a distal end of an electromechanicalsurgical instrument portion of the surgical system of FIG. 1;

FIG. 3 is an exploded assembly view of an outer shell feature and theelectromechanical surgical instrument of FIG. 2;

FIG. 4 is a rear perspective view of a portion of the electromechanicalsurgical instrument of FIG. 2;

FIG. 5 is a partial exploded assembly view of a portion of an adapterand the electromechanical surgical instrument of the surgical system ofFIG. 1;

FIG. 6 is an exploded assembly view of a portion of the adapter of FIG.5;

FIG. 7 is a cross-sectional perspective view of a portion of anarticulation assembly of an adapter;

FIG. 8 is a perspective view of the articulation assembly of FIG. 7;

FIG. 9 is another perspective view of the articulation assembly of FIG.8;

FIG. 10 is an exploded assembly view of a loading unit employed in theelectromechanical surgical system of FIG. 1;

FIG. 11 is a perspective view of an alternative adapter embodiment;

FIG. 12 is a side elevational view of a portion of a loading unit of theadapter of FIG. 11 with the jaws thereof in an open position;

FIG. 13 is another side elevational view of a portion of the loadingunit of FIG. 11 with portions thereof shown in cross-section and thejaws thereof in a closed position;

FIG. 14 is a bottom view of a portion of the loading unit of FIG. 13with portions thereof shown in cross-section;

FIG. 15 is a perspective view of a portion of the loading unit of FIG.14 with a portion of the outer tube shown in phantom lines;

FIG. 16 is a cross-sectional view of a proximal portion of anotheradapter employing various seal arrangements therein;

FIG. 17 is an end cross-sectional view of a portion of the adapter ofFIG. 16;

FIG. 18 is a side elevation al view of another adapter;

FIG. 19 is a cross-sectional view of a portion of the adapter of FIG.18;

FIG. 20 is a rear perspective view of portions of another adapter;

FIG. 21 is a cross-sectional view of another adapter;

FIG. 22 is a perspective view of a portion of another loading unit of anadapter with the jaws thereof in a closed position;

FIG. 23 is a side elevational view of the loading unit of FIG. 22;

FIG. 24 is a perspective view of the loading unit of FIG. 23 after thedynamic clamping assembly has initially contacted positive channelopening features on a channel of the dynamic loading unit;

FIG. 25 is a side elevational view of the loading unit of FIG. 24;

FIG. 26 is another side elevational view of the loading unit of FIGS.22-25 with the jaws thereof in a fully open position;

FIG. 27 is a side elevational view of a portion of another loading unitof an adapter with the jaws thereof in a fully closed position;

FIG. 28 is another side elevational view of the loading unit of FIG. 27with the jaws thereof in a partially open position;

FIG. 29 is another side elevational view of the loading unit of FIGS. 27and 28 with the jaws thereof in a fully open position;

FIG. 30 is a side elevational view of a portion of another loading unitof an adapter with the jaws thereof in a fully open position;

FIG. 31 is another side elevational view of the loading unit of FIG. 30,with the jaws thereof in a partially closed position;

FIG. 32 is another side elevational view of the loading unit of FIGS. 30and 31, with the jaws thereof in a closed position prior to initiationof a firing stroke;

FIG. 33 is a side elevational view of a portion of another loading unitof an adapter with the jaws thereof in a fully open position; and

FIG. 34 is a side elevational view of a portion of another loading unitof an adapter with the jaws thereof in a fully open position.

Corresponding reference characters indicate corresponding partsthroughout the several views. The exemplifications set out hereinillustrate various embodiments of the invention, in one form, and suchexemplifications are not to be construed as limiting the scope of theinvention in any manner.

DETAILED DESCRIPTION

Applicant of the present application owns the following U.S. PatentApplications that were filed on even date herewith and which are eachherein incorporated by reference in their respective entireties:

U.S. patent application Ser. No. ______, entitled SEALED ADAPTERS FORUSE WITH ELECTROMECHANICAL SURGICAL INSTRUMENTS; Attorney Docket No.END8286USNP/170227;

U.S. patent application Ser. No. ______, entitled END EFFECTORS WITHPOSITIVE JAW OPENING FEATURES FOR USE WITH ADAPTERS FORELECTROMECHANICAL SURGICAL INSTRUMENTS; Attorney Docket No.END8277USNP/170219;

U.S. patent application Ser. No. ______, entitled SURGICAL END EFFECTORSWITH PIVOTAL JAWS CONFIGURED TO TOUCH AT THEIR RESPECTIVE DISTAL ENDSWHEN FULLY CLOSED; Attorney Docket No. END8283USNP/170223;

U.S. patent application Ser. No. ______, entitled SURGICAL END EFFECTORSWITH JAW STIFFENER ARRANGEMENTS CONFIGURED TO PERMIT MONITORING OFFIRING MEMBER; Attorney Docket No. END8282USNP/170221;

U.S. patent application Ser. No. ______, entitled ADAPTERS WITH ENDEFFECTOR POSITION SENSING AND CONTROL ARRANGEMENTS FOR USE IN CONNECTIONWITH ELECTROMECHANICAL SURGICAL INSTRUMENTS; Attorney Docket No.END8281USNP/170228;

U.S. patent application Ser. No. ______, entitled DYNAMIC CLAMPINGASSEMBLIES WITH IMPROVED WEAR CHARACTERISTICS FOR USE IN CONNECTION WITHELECTROMECHANICAL SURGICAL INSTRUMENTS; Attorney Docket No.END8279USNP/170222;

U.S. patent application Ser. No. ______, entitled ADAPTERS WITH FIRINGSTROKE SENSING ARRANGEMENTS FOR USE IN CONNECTION WITH ELECTROMECHANICALSURGICAL INSTRUMENTS; Attorney Docket No. END8287USNP/170229;

U.S. patent application Ser. No. ______, entitled ADAPTERS WITH CONTROLSYSTEMS FOR CONTROLLING MULTIPLE MOTORS OF AN ELECTROMECHANICAL SURGICALINSTRUMENT; Attorney Docket No. END8284USNP/170224;

U.S. patent application Ser. No. ______, entitled HANDHELDELECTROMECHANICAL SURGICAL INSTRUMENTS WITH IMPROVED MOTOR CONTROLARRANGEMENTS FOR POSITIONING COMPONENTS OF AN ADAPTER COUPLED THERETO;Attorney Docket No. END8285USNP/170225;

U.S. patent application Ser. No. ______, entitled SYSTEMS AND METHODS OFCONTROLLING A CLAMPING MEMBER FIRING RATE OF A SURGICAL INSTRUMENT;Attorney Docket No. END8280USNP/170226;

U.S. patent application Ser. No. ______, entitled SYSTEMS AND METHODS OFCONTROLLING A CLAMPING MEMBER; Attorney Docket No. END8335USNP/170231;and

U.S. patent application Ser. No. ______, entitled METHODS OF OPERATINGSURGICAL END EFFECTORS; Attorney Docket No. END8298USNP/170218M.

Numerous specific details are set forth to provide a thoroughunderstanding of the overall structure, function, manufacture, and useof the embodiments as described in the specification and illustrated inthe accompanying drawings. Well-known operations, components, andelements have not been described in detail so as not to obscure theembodiments described in the specification. The reader will understandthat the embodiments described and illustrated herein are non-limitingexamples, and thus it can be appreciated that the specific structuraland functional details disclosed herein may be representative andillustrative. Variations and changes thereto may be made withoutdeparting from the scope of the claims.

The terms “comprise” (and any form of comprise, such as “comprises” and“comprising”), “have” (and any form of have, such as “has” and“having”), “include” (and any form of include, such as “includes” and“including”) and “contain” (and any form of contain, such as “contains”and “containing”) are open-ended linking verbs. As a result, a surgicalsystem, device, or apparatus that “comprises,” “has,” “includes” or“contains” one or more elements possesses those one or more elements,but is not limited to possessing only those one or more elements.Likewise, an element of a system, device, or apparatus that “comprises,”“has,” “includes” or “contains” one or more features possesses those oneor more features, but is not limited to possessing only those one ormore features.

The terms “proximal” and “distal” are used herein with reference to aclinician manipulating the handle portion of the surgical instrument.The term “proximal” refers to the portion closest to the clinician andthe term “distal” refers to the portion located away from the clinician.It will be further appreciated that, for convenience and clarity,spatial terms such as “vertical”, “horizontal”, “up”, and “down” may beused herein with respect to the drawings. However, surgical instrumentsare used in many orientations and positions, and these terms are notintended to be limiting and/or absolute.

Various exemplary devices and methods are provided for performinglaparoscopic and minimally invasive surgical procedures. However, thereader will readily appreciate that the various methods and devicesdisclosed herein can be used in numerous surgical procedures andapplications including, for example, in connection with open surgicalprocedures. As the present Detailed Description proceeds, the readerwill further appreciate that the various instruments disclosed hereincan be inserted into a body in any way, such as through a naturalorifice, through an incision or puncture hole formed in tissue, etc. Theworking portions or end effector portions of the instruments can beinserted directly into a patient's body or can be inserted through anaccess device that has a working channel through which the end effectorand elongate shaft of a surgical instrument can be advanced.

A surgical stapling system can comprise a shaft and an end effectorextending from the shaft. The end effector comprises a first jaw and asecond jaw. The first jaw comprises a staple cartridge. The staplecartridge is insertable into and removable from the first jaw; however,other embodiments are envisioned in which a staple cartridge is notremovable from, or at least readily replaceable from, the first jaw. Thesecond jaw comprises an anvil configured to deform staples ejected fromthe staple cartridge. The second jaw is pivotable relative to the firstjaw about a closure axis; however, other embodiments are envisioned inwhich the first jaw is pivotable relative to the second jaw. Thesurgical stapling system further comprises an articulation jointconfigured to permit the end effector to be rotated, or articulated,relative to the shaft. The end effector is rotatable about anarticulation axis extending through the articulation joint. Otherembodiments are envisioned which do not include an articulation joint.

The staple cartridge comprises a cartridge body. The cartridge bodyincludes a proximal end, a distal end, and a deck extending between theproximal end and the distal end. In use, the staple cartridge ispositioned on a first side of the tissue to be stapled and the anvil ispositioned on a second side of the tissue. The anvil is moved toward thestaple cartridge to compress and clamp the tissue against the deck.Thereafter, staples removably stored in the cartridge body can bedeployed into the tissue. The cartridge body includes staple cavitiesdefined therein wherein staples are removably stored in the staplecavities. The staple cavities are arranged in six longitudinal rows.Three rows of staple cavities are positioned on a first side of alongitudinal slot and three rows of staple cavities are positioned on asecond side of the longitudinal slot. Other arrangements of staplecavities and staples may be possible.

The staples are supported by staple drivers in the cartridge body. Thedrivers are movable between a first, or unfired position, and a second,or fired, position to eject the staples from the staple cavities. Thedrivers are retained in the cartridge body by a retainer which extendsaround the bottom of the cartridge body and includes resilient membersconfigured to grip the cartridge body and hold the retainer to thecartridge body. The drivers are movable between their unfired positionsand their fired positions by a sled. The sled is movable between aproximal position adjacent the proximal end and a distal positionadjacent the distal end. The sled comprises a plurality of rampedsurfaces configured to slide under the drivers and lift the drivers, andthe staples supported thereon, toward the anvil.

Further to the above, the sled is moved distally by a firing member. Thefiring member is configured to contact the sled and push the sled towardthe distal end. The longitudinal slot defined in the cartridge body isconfigured to receive the firing member. The anvil also includes a slotconfigured to receive the firing member. The firing member furthercomprises a first cam which engages the first jaw and a second cam whichengages the second jaw. As the firing member is advanced distally, thefirst cam and the second cam can control the distance, or tissue gap,between the deck of the staple cartridge and the anvil. The firingmember also comprises a knife configured to incise the tissue capturedintermediate the staple cartridge and the anvil. It is desirable for theknife to be positioned at least partially proximal to the rampedsurfaces such that the staples are ejected ahead of the knife.

FIG. 1 depicts a motor-driven (electromechanical) surgical system 1 thatmay be used to perform a variety of different surgical procedures. Ascan be seen in that Figure, one example of the surgical system 1includes a powered handheld electromechanical surgical instrument 100that is configured for selective attachment thereto of a plurality ofdifferent surgical tool implements (referred to herein as “adapters”)that are each configured for actuation and manipulation by the poweredhandheld electromechanical surgical instrument. As illustrated in FIG.1, the handheld surgical instrument 100 is configured for selectiveconnection with an adapter 200, and, in turn, adapter 200 is configuredfor selective connection with end effectors that comprise a single useloading unit (“SULU”) or a disposable loading unit (“DLU”) or a multipleuse loading unit (“MULU”). In another surgical system embodiment,various forms of adapter 200 may also be effectively employed with atool drive assembly of a robotically controlled or automated surgicalsystem. For example, the surgical tool assemblies disclosed herein maybe employed with various robotic systems, instruments, components andmethods such as, but not limited to, those disclosed in U.S. Pat. No.9,072,535, entitled SURGICAL STAPLING INSTRUMENTS WITH ROTATABLE STAPLEDEPLOYMENT ARRANGEMENTS, which is hereby incorporated by referenceherein in its entirety.

As illustrated in FIGS. 1 and 2, surgical instrument 100 includes apower-pack 101 and an outer shell housing 10 that is configured toselectively receive and substantially encase the power-pack 101. Thepower pack 101 may also be referred to herein as handle assembly 101.One form of surgical instrument 100, for example, is disclosed inInternational Publication No. WO 2016/057225 A1, InternationalApplication No. PCT/US2015/051837, entitled HANDHELD ELECTROMECHANICALSURGICAL SYSTEM, the entire disclosure of which is hereby incorporatedby reference herein. Various features of surgical instrument 100 willnot be disclosed herein beyond what is necessary to understand thevarious features of the inventions disclosed herein with it beingunderstood that further details may be gleaned from reference to WO2016/057225 A1 and other references incorporated by reference herein.

As illustrated in FIG. 3, outer shell housing 10 includes a distalhalf-section 10 a and a proximal half-section 10 b that is pivotablyconnected to distal half-section 10 a by a hinge 16 located along anupper edge of distal half-section 10 a and proximal half-section 10 b.When joined, distal and proximal half-sections 10 a, 10 b define a shellcavity 10 c therein in which the power-pack 101 is selectively situated.Each of distal and proximal half-sections 10 a, 10 b includes arespective upper shell portion 12 a, 12 b, and a respective lower shellportion 14 a, 14 b. Lower shell portions 14 a, 14 b define a snapclosure feature 18 for selectively securing the lower shell portions 14a, 14 b to one another and for maintaining shell housing 10 in a closedcondition. Distal half-section 10 a of shell housing 10 defines aconnecting portion 20 that is configured to accept a corresponding drivecoupling assembly 210 of adapter 200 (see FIG. 5). Specifically, distalhalf-section 10 a of shell housing 10 has a recess that receives aportion of drive coupling assembly 210 of adapter 200 when adapter 200is mated to surgical instrument 100.

Connecting portion 20 of distal half-section 10 a defines a pair ofaxially extending guide rails 21 a, 21 b that project radially inwardfrom inner side surfaces thereof as shown in FIG. 5. Guide rails 21 a,21 b assist in rotationally orienting adapter 200 relative to surgicalinstrument 100 when adapter 200 is mated to surgical instrument 100.Connecting portion 20 of distal half-section 10 a defines threeapertures 22 a, 22 b, 22 c that are formed in a distally facing surfacethereof and which are arranged in a common plane or line with oneanother. Connecting portion 20 of distal half-section 10 a also definesan elongate slot 24 also formed in the distally facing surface thereof.Connecting portion 20 of distal half-section 10 a further defines afemale connecting feature 26 (see FIG. 2) formed in a surface thereof.Female connecting feature 26 selectively engages with a male connectingfeature of adapter 200.

Distal half-section 10 a of shell housing 10 supports a distal facingtoggle control button 30. The toggle control button 30 is capable ofbeing actuated in a left, right, up and down direction upon applicationof a corresponding force thereto or a depressive force thereto. Distalhalf-section 10 a of shell housing 10 supports a right-side pair ofcontrol buttons 32 a, 32 b (see FIG. 3); and a left-side pair of controlbutton 34 a, 34 b (see FIG. 2). The right-side control buttons 32 a, 32b and the left-side control buttons 34 a, 34 b are capable of beingactuated upon application of a corresponding force thereto or adepressive force thereto. Proximal half-section 10 b of shell housing 10supports a right-side control button 36 a (see FIG. 3) and a left-sidecontrol button 36 b (see FIG. 2). Right-side control button 36 a andleft-side control button 36 b are capable of being actuated uponapplication of a corresponding force thereto or a depressive forcethereto.

Shell housing 10 includes a sterile barrier plate assembly 60selectively supported in distal half-section 10 a. Specifically, thesterile barrier plate assembly 60 is disposed behind connecting portion20 of distal half-section 10 a and within shell cavity 10 c of shellhousing 10. The plate assembly 60 includes a plate 62 rotatablysupporting three coupling shafts 64 a, 64 b, 64 c (see FIGS. 3 and 5).Each coupling shaft 64 a, 64 b, 64 c extends from opposed sides of plate62 and has a tri-lobe transverse cross-sectional profile. Each couplingshaft 64 a, 64 b, 64 c extends through the respective apertures 22 a, 22b, 22 c of connecting portion 20 of distal half-section 10 a when thesterile barrier plate assembly 60 is disposed within shell cavity 10 cof shell housing 10. The plate assembly 60 further includes anelectrical pass-through connector 66 supported on plate 62. Pass-throughconnector 66 extends from opposed sides of plate 62. Pass-throughconnector 66 defines a plurality of contact paths each including anelectrical conduit for extending an electrical connection across plate62. When the plate assembly 60 is disposed within shell cavity 10 c ofshell housing 10, distal ends of coupling shaft 64 a, 64 b, 64 c and adistal end of pass-through connector 66 are disposed or situated withinconnecting portion 20 of distal half-section 10 a of shell housing 10,and are configured to electrically and/or mechanically engage respectivecorresponding features of adapter 200.

Referring to FIGS. 3 and 4, the power-pack or the handle assembly 101includes an inner handle housing 110 having a lower housing portion 104and an upper housing portion 108 extending from and/or supported onlower housing portion 104. Lower housing portion 104 and upper housingportion 108 are separated into a distal half section 110 a and aproximal half-section 110 b connectable to distal half-section 110 a bya plurality of fasteners. When joined, distal and proximal half-sections110 a, 110 b define the inner handle housing 110 having an inner housingcavity 110 c therein in which a power-pack core assembly 106 issituated. Power-pack core assembly 106 is configured to control thevarious operations of surgical instrument 100.

Distal half-section 110 a of inner handle housing 110 supports a distaltoggle control interface 130 that is in operative registration with thedistal toggle control button 30 of shell housing 10. In use, when thepower-pack 101 is disposed within shell housing 10, actuation of thetoggle control button 30 exerts a force on toggle control interface 130.Distal half-section 110 a of inner handle housing 110 also supports aright-side pair of control interfaces (not shown), and a left-side pairof control interfaces 132 a, 132 b. In use, when the power-pack 101 isdisposed within shell housing 10, actuation of one of the right-sidepair of control buttons or the left-side pair of control button ofdistal half-section 10 a of shell housing 10 exerts a force on arespective one of the right-side pair of control interfaces 132 a, 132 bor the left-side pair of control interfaces 132 a, 132 b of distalhalf-section 110 a of inner handle housing 110.

With reference to FIGS. 1-5, inner handle housing 110 provides a housingin which power-pack core assembly 106 is situated. Power-pack coreassembly 106 includes a battery circuit 140, a controller circuit board142 and a rechargeable battery 144 configured to supply power to any ofthe electrical components of surgical instrument 100. Controller circuitboard 142 includes a motor controller circuit board 142 a, a maincontroller circuit board 142 b, and a first ribbon cable 142 cinterconnecting motor controller circuit board 142 a and main controllercircuit board 142 b. Power-pack core assembly 106 further includes adisplay screen 146 supported on main controller circuit board 142 b.Display screen 146 is visible through a clear or transparent window 110d (see FIG. 3) provided in proximal half-section 110 b of inner handlehousing 110. It is contemplated that at least a portion of inner handlehousing 110 may be fabricated from a transparent rigid plastic or thelike. It is further contemplated that shell housing 10 may eitherinclude a window formed therein (in visual registration with displayscreen 146 and with window 110 d of proximal half-section 110 b of innerhandle housing 110, and/or shell housing 10 may be fabricated from atransparent rigid plastic or the like.

Power-pack core assembly 106 further includes a first motor 152, asecond motor 154, and a third motor 156 that are supported by motorbracket 148 and are each electrically connected to controller circuitboard 142 and battery 144. Motors 152, 154, 156 are disposed betweenmotor controller circuit board 142 a and main controller circuit board142 b. Each motor 152, 154, 156 includes a respective motor shaft 152 a,154 a, 156 a extending therefrom. Each motor shaft 152 a, 154 a, 156 ahas a tri-lobe transverse cross-sectional profile for transmittingrotative forces or torque. Each motor 152, 154, 156 is controlled by arespective motor controller. Rotation of motor shafts 152 a, 154 a, 156a by respective motors 152, 154, 156 function to drive shafts and/orgear components of adapter 200 in order to perform the variousoperations of surgical instrument 100. In particular, motors 152, 154,156 of power-pack core assembly 106 are configured to drive shaftsand/or gear components of adapter 200.

As illustrated in FIGS. 1 and 5, surgical instrument 100 is configuredfor selective connection with adapter 200, and, in turn, adapter 200 isconfigured for selective connection with end effector 500. Adapter 200includes an outer knob housing 202 and an outer tube 206 that extendsfrom a distal end of knob housing 202. Knob housing 202 and outer tube206 are configured and dimensioned to house the components of adapterassembly 200. Outer tube 206 is dimensioned for endoscopic insertion, inparticular, that outer tube is passable through a typical trocar port,cannula or the like. Knob housing 202 is dimensioned to not enter thetrocar port, cannula of the like. Knob housing 202 is configured andadapted to connect to connecting portion 20 of the outer shell housing10 of surgical instrument 100.

Adapter 200 is configured to convert a rotation of either of first orsecond coupling shafts 64 a, 64 b of surgical instrument 100 into axialtranslation useful for operating a drive assembly 540 and anarticulation link 560 of end effector 500, as illustrated in FIG. 10 andas will be described in greater detail below. As illustrated in FIG. 6,adapter 200 includes the proximal inner housing assembly 204 thatrotatably supports a first rotatable proximal drive shaft 212, a secondrotatable proximal drive shaft 214, and a third rotatable proximal driveshaft 216 therein. Each proximal drive shaft 212, 214, 216 functions asa rotation receiving member to receive rotational forces from respectivecoupling shafts 64 a, 64 b and 64 c of surgical instrument 100. Inaddition, the drive coupling assembly 210 of adapter 200 is alsoconfigured to rotatably support first, second and third connectorsleeves 218, 220 and 222, respectively, arranged in a common plane orline with one another. Each connector sleeve 218, 220, 222 is configuredto mate with respective first, second and third coupling shafts 64 a, 64b, 64 c of surgical instrument 100, as described above. Each connectorsleeves 218, 222, 220 is further configured to mate with a proximal endof respective first, second, and third proximal drive shafts 212, 214,216 of adapter 200.

Drive coupling assembly 210 of adapter 200 also includes a first, asecond, and a third biasing member 224, 226, and 228 disposed distallyof respective first, second, and third connector sleeves 218, 220, 222.Each biasing members 224, 226, and 228 is disposed about respectivefirst, second, and third rotatable proximal drive shaft 212, 214, and216. Biasing members 224, 226, and 228 act on respective connectorsleeves 218, 222, and 220 to help maintain connector sleeves 218, 222.and 220 engaged with the distal end of respective coupling shafts 64 a,64 b, and 64 c of surgical instrument 100 when adapter 200 is connectedto surgical instrument 100.

Also in the illustrated arrangement, adapter 200 includes first, second,and third drive converting assemblies 240, 250, 260, respectively, thatare each disposed within inner housing assembly 204 and outer tube 206.Each drive converting assembly 240, 250, 260 is configured and adaptedto transmit or convert a rotation of a first, second, and third couplingshafts 64 a, 64 b, and 64 c of surgical instrument 100 into axialtranslation of an articulation driver or bar 258 of adapter 200, toeffectuate articulation of end effector 500; a rotation of a ring gear266 of adapter 200, to effectuate rotation of adapter 200; or axialtranslation of a distal drive member 248 of adapter 200 to effectuateclosing, opening, and firing of end effector 500.

Still referring to FIG. 6, first force/rotation transmitting/convertingassembly 240 includes first rotatable proximal drive shaft 212, which,as described above, is rotatably supported within inner housing assembly204. First rotatable proximal drive shaft 212 includes a non-circular orshaped proximal end portion configured for connection with firstconnector sleeve 218 which is connected to respective first couplingshaft 64 a of surgical instrument 100. First rotatable proximal driveshaft 212 includes a threaded distal end portion 212 b. Firstforce/rotation transmitting/converting assembly 240 further includes adrive coupling nut 244 that threadably engages the threaded distal endportion 212 b of first rotatable proximal drive shaft 212, and which isslidably disposed within outer tube 206. Drive coupling nut 244 isslidably keyed within proximal core tube portion of outer tube 206 so asto be prevented from rotation as first rotatable proximal drive shaft212 is rotated. In this manner, as the first rotatable proximal driveshaft 212 is rotated, drive coupling nut 244 is translated alongthreaded distal end portion 212 b of first rotatable proximal driveshaft 212 and, in turn, through and/or along outer tube 206.

First force/rotation transmitting/converting assembly 240 furtherincludes a distal drive member 248 that is mechanically engaged withdrive coupling nut 244, such that axial movement of drive coupling nut244 results in a corresponding amount of axial movement of distal drivemember 248. The distal end portion of distal drive member 248 supports aconnection member 247 configured and dimensioned for selectiveengagement with an engagement member 546 of a drive assembly 540 of endeffector 500 (FIG. 10). Drive coupling nut 244 and/or distal drivemember 248 function as a force transmitting member to components of endeffector 500. In operation, as first rotatable proximal drive shaft 212is rotated, as a result of the rotation of first coupling shaft 64 a ofsurgical instrument 100, drive coupling nut 244 is translated axiallyalong first rotatable proximal drive shaft 212. As drive coupling nut244 is translated axially along first rotatable proximal drive shaft212, distal drive member 248 is translated axially relative to outertube 206. As distal drive member 248 is translated axially, withconnection member 247 connected thereto and engaged with a hollow drivemember 548 attached to drive assembly 540 of end effector 500 (FIG. 10),distal drive member 248 causes concomitant axial translation of driveassembly 540 of end effector 500 to effectuate a closure of a toolassembly portion 600 of the end effector 500 and a firing of variouscomponents within the tool assembly.

Still referring to FIG. 6, second drive converting assembly 250 ofadapter 200 includes second proximal drive shaft 214 that is rotatablysupported within inner housing assembly 204. Second rotatable proximaldrive shaft 214 includes a non-circular or shaped proximal end portionconfigured for connection with second coupling shaft 64 c of surgicalinstrument 100. Second rotatable proximal drive shaft 214 furtherincludes a threaded distal end portion 214 a configured to threadablyengage an articulation bearing housing 253 of an articulation bearingassembly 252. Referring to FIGS. 6-9, the articulation bearing housing253 supports an articulation bearing 255 that has an inner race 257 thatis independently rotatable relative to an outer race 259. Articulationbearing housing 253 has a non-circular outer profile, for exampletear-dropped shaped, that is slidably and non-rotatably disposed withina complementary bore (not shown) of inner housing hub 204 a. Seconddrive converting assembly 250 of adapter 200 further includesarticulation bar 258 that has a proximal portion that is secured toinner race 257 of articulation bearing 255. A distal portion ofarticulation bar 258 includes a slot 258 a therein, which is configuredto accept a hook 562 the articulation link 560 (FIG. 10) of end effector500. Articulation bar 258 functions as a force transmitting member tocomponents of end effector 500. In the illustrated arrangement and asfurther discussed in WO 2016/057225 A1, articulation bearing assembly252 is both rotatable and longitudinally translatable and is configuredto permit free, unimpeded rotational movement of end effector 500 whenits first and second jaw members 610, 700 are in an approximatedposition and/or when jaw members 610, 700 are articulated.

In operation, as second proximal drive shaft 214 is rotated, thearticulation bearing assembly 252 is axially translated along threadeddistal end portion 214 a of second proximal drive shaft 214, which inturn, causes articulation bar 258 to be axially translated relative toouter tube 206. As articulation bar 258 is translated axially,articulation bar 258, being coupled to articulation link 560 of endeffector 500, causes concomitant axial translation of articulation link560 of end effector 500 to effectuate an articulation of tool assembly600. Articulation bar 258 is secured to inner race 257 of articulationbearing 253 and is thus free to rotate about the longitudinal axisrelative to outer race 259 of articulation bearing 253.

As illustrated in FIG. 6, adapter 200 includes a third drive convertingassembly 260 that is supported in inner housing assembly 204. Thirddrive converting assembly 260 includes rotation ring gear 266 that isfixedly supported in and connected to outer knob housing 202. Ring gear266 defines an internal array of gear teeth 266 a and includes a pair ofdiametrically opposed, radially extending protrusions 266 b. Protrusions266 b are configured to be disposed within recesses defined in outerknob housing 202, such that rotation of ring gear 266 results inrotation of outer knob housing 202, and vice a versa. Third driveconverting assembly 260 further includes third rotatable proximal driveshaft 216 which, as described above, is rotatably supported within innerhousing assembly 204. Third rotatable proximal drive shaft 216 includesa non-circular or shaped proximal end portion that is configured forconnection with third connector 220. Third rotatable proximal driveshaft 216 includes a spur gear 216 keyed to a distal end thereof. Areversing spur gear 264 inter-engages spur gear 216 a of third rotatableproximal drive shaft 216 to gear teeth 266 a of ring gear 266. Inoperation, as third rotatable proximal drive shaft 216 is rotated, dueto a rotation of the third coupling shaft 64 b of surgical instrument100, spur gear 216 a of third rotatable proximal drive shaft 216 engagesreversing gear 264 causing reversing gear 264 to rotate. As reversinggear 264 rotates, ring gear 266 also rotates thereby causing outer knobhousing 202 to rotate. Rotation of the outer knob housing 202 causes theouter tube 206 to rotate about longitudinal axis of adapter 200. Asouter tube 206 is rotated, end effector 500 that is connected to adistal end portion of adapter 200, is also rotated about a longitudinalaxis of adapter 200.

Adapter 200 further includes an attachment/detachment button 272 (FIG.5) that is supported on a stem 273 (FIG. 6) that projects from drivecoupling assembly 210 of adapter 200. The attachment/detachment button272 is biased by a biasing member (not shown) that is disposed within oraround stem 273, to an un-actuated condition. Button 272 includes a lipor ledge that is configured to snap behind a corresponding lip or ledgeof connecting portion 20 of the surgical instrument 100. As alsodiscussed in WO 2016/057225 A1, the adapter 200 may further include alock mechanism 280 for fixing the axial position of distal drive member248. As can be seen in FIG. 21, for example, lock mechanism 280 includesa button 282 that is slidably supported on outer knob housing 202. Lockbutton 282 is connected to an actuation bar (not shown) that extendslongitudinally through outer tube 206. Actuation bar moves upon amovement of lock button 282. In operation, in order to lock the positionand/or orientation of distal drive member 248, a user moves lock button282 from a distal position to a proximal position, thereby causing thelock out (not shown) to move proximally such that a distal face of thelock out moves out of contact with camming member 288, which causescamming member 288 to cam into recess 249 of distal drive member 248. Inthis manner, distal drive member 248 is prevented from distal and/orproximal movement. When lock button 282 is moved from the proximalposition to the distal position, the distal end of actuation bar movesdistally into the lock out (not shown), against the bias of a biasingmember (not shown), to force camming member 288 out of recess 249,thereby allowing unimpeded axial translation and radial movement ofdistal drive member 248.

Returning again to FIG. 6, adapter 200 includes an electrical assembly290 supported on and in outer knob housing 202 and inner housingassembly 204. Electrical assembly 290 includes a plurality of electricalcontact blades 292, supported on a circuit board 294, for electricalconnection to pass-through connector of plate assembly of shell housing10 of surgical instrument 100. Electrical assembly 290 serves to allowfor calibration and communication information (i.e., life-cycleinformation, system information, force information) to pass to thecircuit board of surgical instrument 100 via an electrical receptacleportion of the power-pack core assembly 106 of surgical instrument 100.Electrical assembly 290 further includes a strain gauge 296 that iselectrically connected to circuit board 294. Strain gauge 296 is mountedwithin the inner housing assembly 204 to restrict rotation of the straingauge 296 relative thereto. First rotatable proximal drive shaft 212extends through strain gauge 296 to enable the strain gauge 296 toprovide a closed-loop feedback to a firing/clamping load exhibited byfirst rotatable proximal drive shaft 212. Electrical assembly 290 alsoincludes a slip ring 298 that is non-rotatably and slidably disposedalong drive coupling nut 244 of outer tube 206. Slip ring 298 is inelectrical connection with circuit board 294 and serves to permitrotation of first rotatable proximal drive shaft 212 and axialtranslation of drive coupling nut 244 while still maintaining electricalcontact of slip ring 298 with at least another electrical componentwithin adapter 200, and while permitting the other electrical componentsto rotate about first rotatable proximal drive shaft 212 and drivecoupling nut 244.

Still referring to FIG. 6, inner housing assembly 204 includes a hub 205that has a distally oriented annular wall 207 that defines asubstantially circular outer profile. Hub 205 includes a substantiallytear-drop shaped inner recess or bore that is shaped and dimensioned toslidably receive articulation bearing assembly 252 therewithin. Innerhousing assembly 204 further includes a ring plate 254 that is securedto a distal face of distally oriented annular wall 207 of hub 204 a.Ring plate 254 defines an aperture 254 a therethrough that is sized andformed therein so as to be aligned with second proximal drive shaft 214and to rotatably receive a distal tip thereof. In this manner, thedistal tip of the second proximal drive shaft 214 is supported andprevented from moving radially away from a longitudinal rotational axisof second proximal drive shaft 214 as second proximal drive shaft 214 isrotated to axially translate articulation bearing assembly 252.

Turning next to FIG. 10, in one example, the end effector 500 may beconfigured for a single use (“disposable loading unit—DLU”) and besimilar to those DLU's disclosed in U.S. Patent Application PublicationNo. 2010/0301097, entitled LOADING UNIT HAVING DRIVE ASSEMBLY LOCKINGMECHANISM, now U.S. Pat. No. 9,795,384, U.S. Patent ApplicationPublication No. 2012/0217284, entitled LOCKING MECHANISM FOR USE WITHLOADING UNITS, now U.S. Pat. No. 8,292,158, and U.S. Patent ApplicationPublication No. 2015/0374371, entitled ADAPTER ASSEMBLIES FORINTERCONNECTING SURGICAL LOADING UNITS AND HANDLE ASSEMBLIES, the entiredisclosures of each such references being hereby incorporated byreference herein. It is also contemplated that the end effector 500 maybe configured for multiple uses (MULU) such as those end effectorsdisclosed in U.S. Patent Application Publication No. 2017/0095250,entitled MULTI-USE LOADING UNIT, the entire disclosure of which ishereby incorporated by reference herein.

The depicted surgical instrument 100 fires staples, but it may beadapted to fire any other suitable fastener such as clips and two-partfasteners. In the illustrated arrangement, the end effector 500comprises a loading unit 510. The loading unit 510 comprises a proximalbody portion 520 and a tool assembly 600. Tool assembly 600 includes apair of jaw members including a first jaw member 610 that comprises ananvil assembly 612 and a second jaw member 700 that comprises acartridge assembly 701. One jaw member is pivotal in relation to theother to enable the clamping of tissue between the jaw members. Thecartridge assembly 701 is movable in relation to anvil assembly 612 andis movable between an open or unclamped position and a closed orapproximated position. However, the anvil assembly 612, or both thecartridge assembly 701 and the anvil assembly 612, can be movable.

The cartridge assembly 701 has a cartridge body 702 and in someinstances a support plate 710 that are attached to a channel 720 by asnap-fit connection, a detent, latch, or by another type of connection.The cartridge assembly 701 includes fasteners or staples 704 that aremovably supported in a plurality of laterally spaced staple retentionslots 706, which are configured as openings in a tissue contactingsurface 708. Each slot 706 is configured to receive a fastener or stapletherein. Cartridge body 702 also defines a plurality of cam wedge slotswhich accommodate staple pushers 709 and which are open on the bottom(i.e., away from tissue-contacting surface) to allow an actuation sled712 to pass longitudinally therethrough. The cartridge assembly 701 isremovable from channel 720 after the staples have been fired fromcartridge body 702. Another removable cartridge assembly is capable ofbeing loaded onto channel 720, such that surgical instrument 100 can beactuated again to fire additional fasteners or staples. Further detailsconcerning the cartridge assembly may be found, for example, in U.S.Patent Application Publication No. 2017/0095250 as well as various otherreferences that have been incorporated by reference herein.

Cartridge assembly 701 is pivotal in relation to anvil assembly 612 andis movable between an open or unclamped position and a closed or clampedposition for insertion through a cannula of a trocar. Proximal bodyportion 520 includes at least a drive assembly 540 and an articulationlink 560. In one arrangement, drive assembly 540 includes a flexibledrive beam 542 that has a distal end 544 and a proximal engagementsection 546. A proximal end of the engagement section 546 includesdiametrically opposed inwardly extending fingers 547 that engage ahollow drive member 548 to fixedly secure drive member 548 to theproximal end of beam 542. Drive member 548 defines a proximal portholewhich receives connection member 247 of drive tube 246 of first driveconverting assembly 240 of adapter 200 when the end effector 500 isattached to the distal end of the adapter 200.

End effector 500 further includes a housing assembly 530 that comprisesan outer housing 532 and an inner housing 534 that is disposed withinouter housing 532. First and second lugs 536 are each disposed on anouter surface of a proximal end 533 of outer housing 532 and areconfigured to operably engage the distal end of the adapter 200 asdiscussed in further detail in WO 2016/057225 A1.

With reference to FIG. 10, for example, anvil assembly 612 includes ananvil cover 630 and an anvil plate 620, which includes a plurality ofstaple forming depressions. Anvil plate 620 is secured to an undersideof anvil cover 630. When tool assembly 600 is in the approximatedposition, staple forming depressions are positioned in juxtaposedalignment with staple receiving slots of the cartridge assembly 701.

The tool assembly 600 includes a mounting assembly 800 that comprises anupper mounting portion 810 and a lower mounting portion 812. A mountingtail 632 protrudes proximally from a proximal end 631 of the anvil cover630. A centrally-located pivot member 814 extends from each upper andlower mounting portions 810 and 812 through openings 822 that are formedin coupling members 820. In at least one arrangement, the pivot member814 of the upper mounting portion 810 also extends through an opening634 in the mounting tail 632 as well. Coupling members 820 each includean interlocking proximal portion 824 that is configured to be receivedin corresponding grooves formed in distal ends of the outer housing 532and inner housing 534. Proximal body portion 520 of end effector 500includes articulation link 560 that has a hooked proximal end 562. Thearticulation link 560 is dimensioned to be slidably positioned within aslot in the inner housing. A pair of H-block assemblies 830 arepositioned adjacent the distal end of the outer housing 532 and adjacentthe distal end 544 of axial drive assembly 540 to prevent outwardbuckling and bulging of the flexible drive beam 542 during articulationand firing of surgical stapling apparatus 10. Each H-block assembly 830includes a flexible body 832 which includes a proximal end fixedlysecured to the distal end of the outer housing 532 and a distal end thatis fixedly secured to mounting assembly 800. In one arrangement, adistal end 564 of the articulation link is pivotally pinned to the rightH block assembly 830. Axial movement of the articulation link 560 willcause the tool assembly to articulate relative to the body portion 520.

FIGS. 11-15 illustrate an adapter 200′ that is substantially identicalto adapter 200 described above, except for the differences noted below.As can be seen in FIG. 11, the adapter 200′ includes an outer tube 206that has a proximal end portion 910 that has a first diameter “FD” andis mounted within the outer knob housing 202. The proximal end portion910 may be coupled to the inner housing assembly 204 or otherwisesupported therein in the manners discussed in further detail in WO2016/057225 A1 for example. The proximal end portion 910 extendsproximally from a central tube portion 912 that has a second diameter“SD”. In the illustrated embodiment, an end effector 500 is coupled to adistal end 914 of a shaft assembly 203 or outer tube 206. The outer tube206 defines a longitudinal axis LA that extends between the proximal endportion 910 and the distal end 914 as can be seen in FIG. 11. As can beseen in FIGS. 10 and 11, an outer sleeve 570 of the proximal bodyportion 520 of the end effector 500 has a distal end portion 572 and aproximal end portion 574. The proximal end portion 574 has a diameterSD′ that is approximately equal to the second diameter SD of the centraltube portion 912. The distal end portion 572 has a third diameter “TD”.In one arrangement, FD and TD are approximately equal and greater thanSD. Other arrangements are contemplated wherein FD and TD are not equal,but each are greater than SD. However, it is preferable that for mostcases FD and TD are dimensioned for endoscopic insertion through atypical trocar port, cannula or the like. In at least one arrangement(FIG. 11), the outer sleeve 570 is formed with a flat or scalloped side576 to facilitate improved access within the patient while effectivelyaccommodating the various drive and articulation components of theadapter 200′. In addition, by providing the central tube portion 912with a reduced diameter may afford the adapter 200′ with improvedthoracic in-between rib access.

In at least one arrangement, channel 720, which may be machined or madeof sheet metal, includes a pair of proximal holes 722 (FIG. 10) that areconfigured to align with a pair of corresponding holes 636 in the anvilcover 630 to receive corresponding pins or bosses 638 (FIG. 12) tofacilitate a pivotal relationship between anvil assembly 612 andcartridge assembly 701. In the illustrated example, a dynamic clampingassembly 550 is attached to or formed at the distal end 544 of theflexible drive beam 542. The dynamic clamping assembly 550 includes avertical body portion 552 that has a tissue cutting surface 554 formedthereon or attached thereto. See FIG. 10, for example. An anvilengagement feature 556 is formed on one end of the body portion 552 andcomprises an anvil engagement tab 557 that protrudes from each lateralside of the body portion 552. Similarly, a channel engagement feature558 is formed on the other end of the of the body portion 552 andcomprises a channel engagement tab 559 that protrudes from each lateralside of the body portion 552. See FIG. 15.

As indicated above, the anvil assembly 612 includes an anvil plate 620.The anvil plate 620 includes an elongate slot 622 that is configured toaccommodate the body portion 552 of the dynamic clamping assembly 550 asthe dynamic clamping assembly 550 is axially advanced during the firingprocess. The elongate slot 622 is defined between two anvil plate ledges624 that extend along each lateral side of the elongate slot 622. SeeFIG. 10. As the dynamic clamping assembly 550 is distally advanced, theanvil engagement tabs 557 slidably engage the anvil plate ledges 624 toretain the anvil assembly 612 clamped onto the target tissue. Similarly,during the firing operation, the body portion 552 of the dynamicclamping assembly 550 extends through a central slot in the channel 720and the channel engagement tabs 559 slidably engage channel ledges 725extending along each side of the central channel slot to retain thecartridge assembly 701 clamped onto the target tissue.

Turning to FIGS. 13 and 15, the channel 720 defines a docking areagenerally designated as 730 that is configured to accommodate thedynamic clamping assembly 550 when it is in its proximal most positionreferred to herein as an unfired or starting position. In particular,the docking area 730 is partially defined by planar docking surfaces 732that provides clearance between the channel engagement tabs 559 on thedynamic clamping assembly 550 to enable the cartridge assembly 701 topivot to a fully opened position. A ramped or camming surface 726extends from a distal end of each of the docking surfaces 732. Rampedsurface 726 is engaged by the dynamic clamping assembly 550 in order tomove the anvil assembly 612 and the cartridge assembly 701 with respectto one another. Similar camming surface could be provided on the anvilassembly 612 in other embodiments. It is envisioned that ramped surfaces726 may also facilitate the alignment and/or engagement between channel720 and support plate 620 and/or cartridge body 702. As the driveassembly 540 is distally advanced (fired), the channel engagement tabs559 on the dynamic clamping assembly 550 engage the corresponding rampedsurfaces 726 to apply a closing motion to the cartridge assembly 701thus closing the cartridge assembly 701 and the anvil assembly 612.Further distal translation of the dynamic clamping assembly 550 causesthe actuation sled 712 to move distally through cartridge body 702,which causes cam wedges 713 of actuation sled 712 to sequentially engagestaple pushers 709 to move staple pushers 709 vertically within stapleretention slots 706 and eject staples 704 into staple formingdepressions of anvil plate 620. Subsequent to the ejection of staples704 from retention slots 706 (and into tissue), the cutting edge 554 ofthe dynamic clamping assembly 550 severs the stapled tissue as thetissue cutting edge 554 on the vertical body portion 552 of the dynamicclamping assembly 550 travels distally through a central slot 703 ofcartridge body 702. After staples 704 have been ejected from cartridgebody 702 and a user wishes to use the same instrument 10 to fireadditional staples 704 (or another type of fastener or knife), the usercan remove the loading unit 510 from the adapter 200′ and replace itwith another fresh or unspent loading unit. In an alternativearrangement, the user may simply remove the spent cartridge body 702 andreplace it with a fresh unspent or unfired cartridge body 702.

During use of conventional adapters, debris and body fluids can migrateinto the outer tube of the adapter and detrimentally hamper theoperation of the adapter articulation and firing drive systems. Inegregious cases, such debris and fluids infiltrate into the innerhousing assembly of the adapter which may cause the electricalcomponents supported therein to short out and malfunction. Further, dueto limited access to the interior of the outer tube of the adapter, suchdebris and fluids are difficult to remove therefrom which can prevent orreduce the ability to reuse the adapter.

Turning to FIGS. 16 and 17, in one arrangement, at least one first seal230 is provided between the proximal inner housing assembly 204 and thefirst rotatable proximal drive shaft 212 to prevent fluid/debrisinfiltration within and proximal to the proximal inner housing assembly204. In addition, at least one second seal 232 is provided between thearticulation bar 258 and the outer tube 206 to prevent fluid/debris frompassing therebetween to enter the proximal inner housing assembly 204.At least one third housing seal 233 may be provided around a hub 205 ofthe proximal inner housing 204 to establish a seal between the hub 205and the outer knob housing 202. The first, second, and third seals 230,232, 233 may comprise, for example, flexible O-rings manufactured fromrubber or other suitable material.

In other arrangements, it may be desirable for the first and secondseals 230, 232 to be located in the adapter 200 distal to the electroniccomponents housed within the outer knob housing 202. For example, toprevent fluids/debris from fouling/shorting the slip ring assembly 298,it is desirable establish seals between the various moving components ofthe adapter 200 that are operably supported within the outer tube 206 ina location or locations that are each distal to the slip ring assembly298, for example. The seals 230, 232 may be supported in the wall of theouter tube and/or in mounting member 234 or other separate mountingmember/bushing/housing supported within the outer tube 206 andconfigured to facilitate axial movement of the distal drive member 248as well as the articulation bar 258 while establishing a fluid-tightseal between the bushing and/or outer tube and the distal drive member248 and the articulation bar 258. See FIGS. 18 and 20. In the embodimentillustrated in FIG. 19 for example, the first seal 230 may additionallyhave wiper features 231 that also slidably engage the distal drivemember 248 to prevent fluid/debris D from infiltrating in the proximaldirection PD into the proximal inner housing assembly 204. In at leastone arrangement to enable debris and fluids that have collected in theouter tube 206 distal to the first and second seals 230, 232, at leasttwo flushing ports 236, 238 are provided within the outer tube 206. Seee.g., FIGS. 18 and 20. The axially spaced flushing ports 236, 238 arelocated distal to the first and second seals 230, 232. A flushingsolution (e.g., cleaning fluid, saline fluid, air, etc.) may be enteredinto one or more port(s) to force the errant debris and fluid out of oneor more other port(s).

The ability to open the jaws of an endocutter to a large angle enablesmore tissue to be placed between them. In addition, having the abilityto open the jaws to a larger angle also makes it easier for a user toremove the tissue from between the jaws after the stapling process hasbeen completed which helps to simplify the cartridge reloading processwhen reloadable units are employed. Thus, it is desirable to optimizethe speeds and forces required to open the jaws of an end effector suchas an endocutter. In the past, a variety of methods have been employedto open the jaws of an endocutter. In one arrangement, a spring wasemployed to apply a biasing opening force to the jaws. However, suchspring opening arrangements may increase the amount of forces needed toclose the jaws. They may also have relatively limited motion and can bedifficult to install within the end effector.

FIGS. 22-25 illustrate use of an alternative channel 720′ of a secondjaw. The channel 720′ may be identical to channel 720 described above,except for the differences noted below. In the illustrated arrangement,for example, the channel 720′ includes a positive channel openingfeature 740 that comprises a ramp surface 742 that is located on eachside of a central slot 724 in the channel 720′. Each ramp 742 terminatesin a planar upper surface 744. As can be further seen in FIG. 22, achannel ledge 725 is formed on each side of the elongate central slot724 on the top side of the channel 720′. During the firing operation,the body portion 552 of the dynamic clamping assembly 550 extendsthrough the central slot 724 and the channel engagement tabs 559slidably engage the channel ledges 725 extending along each side of thecentral slot 724 to retain the cartridge assembly 701 clamped onto thetarget tissue.

FIGS. 22 and 23 illustrate a position of the dynamic clamping assembly550 as it is retracted in the proximal direction PD. As can be seen inthose Figures, the channel engagement tabs 559 have not yet contactedthe ramps 742 of the positive channel opening features 740. FIGS. 24 and25 illustrate initial contact of the channel engagement tabs 559 withthe ramp portions 742 of the corresponding positive channel openingfeatures 740. As can be seen in FIG. 25 the channel 720′ has started toopen (i.e., move away from the anvil assembly 612). FIG. 26 illustratesthe position of the dynamic clamping assembly 550 in its startingposition wherein the channel 720′ is in its fully open position. As canbe seen in that Figure, for example, the channel engagement tabs 559 arein engagement with the planar upper surfaces 744 of the ramps 742. Sucharrangement may be employed to open the jaws (anvil assembly 612 andcartridge assembly 701) without the use of a spring or springs. However,other variations are contemplated wherein an opening spring is alsoemployed in addition to the positive channel opening features 740.

FIGS. 27-29 illustrate an alternative arrangement where, in addition tothe positive channel opening features 740 on the channel 720′, positiveanvil opening features 627 are provided on a proximal end 621 of theanvil plate 620′. The anvil plate 620′ may be identical to anvil plate620 described above, except for the differences noted below. Thepositive anvil opening features 627 each comprise an anvil opening ramp628 provided on each side of the elongate slot 622 (see FIG. 10). Asdiscussed above, the anvil plate has an elongate slot 622 that definestwo elongate ledges 624 upon which anvil engagement tabs 557 of thedynamic clamping assembly 550 ride. The positive channel openingfeatures 740 on the channel 720′ are longitudinally offset from thepositive anvil opening features 627 on the anvil plate 620′. In theillustrated example, the positive channel opening features 740 on thechannel 720′ are distal to the positive anvil opening features 627 onthe anvil plate 620′. FIG. 27 illustrates initial contact of the channelengagement tabs 559 with the ramp surfaces 742 of the positive channelopening features 740. For reference purposes, the distance between thedistal edge of each channel engagement tab 559 and the jaw axis JA islabeled as distance PDD₁. FIG. 28 illustrates the position of thedynamic clamping assembly 550 after the channel engagement tabs 559 havemoved up the ramps 742 onto the planar upper surfaces 744 of thepositive channel opening features 740. When in that position, the anvilengagement tabs 557 on the dynamic clamping assembly 550 have contactedthe anvil opening ramps 628 of the anvil opening features 627. Thus,comparing the proximal travel distance of the dynamic clamping assemblybetween FIGS. 27 and 28: PDD₂>PDD₁. FIG. 29 illustrates position of thedynamic clamping assembly 550 after it has moved back to its startingposition and the anvil engagement tabs 557 on the dynamic clampingassembly 550 have completely moved past the anvil opening ramps 628 ofthe anvil opening features 627 and the jaws 700′ and 610′ are in theirfully open positions. Thus, comparing the proximal travel distance ofthe dynamic clamping assembly between FIGS. 28 and 29: PDD₃>PDD₂. Suchpositive jaw opening features 740, 627 use either/both longitudinalforces to drive the opening of the jaws or orthogonal forces to drivethe opening motions. In the above described example, the positive jawopening features are longitudinally offset. In other arrangements,however, the anvil engagement tabs 557 contact the ramps 628 atapproximately the same time that the tabs 559 contact the ramps 742.

Another feature employed by a channel 720″ relates to closure rampsformed on the channel 720″. The channel 720″ may be identical to channel720′ or 720 described above, except for the differences noted below. Ascan be seen in FIGS. 30-32, for example, a first closure ramp segment726 a is formed on each side of the elongate slot (not shown) in thechannel 720″. Each first closure ramp segment 726 a transitions into ahorizontal plateau ramp segment 727 which in turn transitions into asecond closure ramp segment 728. Each second closure ramp segment 728transitions to a corresponding channel ledge 725. In one arrangement,the slope of each of the first closure ramp segments 726 a is the sameas the slope of the second closure ramp segments 728. In otherarrangements, the slopes are different. FIG. 30 illustrates the positionof the channel engagement tabs 559 on the dynamic clamping assembly 550when the jaws 610″, 700″are in their fully open position. FIG. 31illustrates a position of the dynamic clamping assembly 550 after it hasbeen moved distally so as to bring the channel engagement tabs 559 intosliding engagement with the proximal closure ramp segments 726 a so asto begin the jaw closure process. FIG. 32 illustrates another positionof the dynamic clamping assembly 550 after it has further moved in thedistal direction DD so as to bring the channel engagement tabs 559 intosliding engagement with the plateau ramp segment 727 and prior tostarting a firing stroke wherein the channel engagement tabs 559slidably engage the channel ledges 725 on the channel 720″.

Another desirable attribute for surgical end effectors relates to “jawaperture”. “Jaw aperture” may refer to the angle between a stapleforming surface on the anvil plate and a tissue contacting surface ofthe staple cartridge. In existing versions of DLU's, SULU's and MULU's,the upper channel engagement feature or tab on the dynamic clampingunit, when the dynamic clamping unit is in its proximal most or startingposition, is generally positioned directly above or distal to a jawpivot axis about which the cartridge assembly pivots relative to theanvil assembly. Such arrangements commonly limit the jaws from openingrelative to each other more than 18-23 mm, for example.

One aspect of the present disclosure involves the formation of a“docking” or “parking” area for the dynamic clamping member when thedynamic clamping member is in its proximal most or starting position.For example, FIG. 33 illustrates an end effector 1500 that includes aparking or docking area 730 for the dynamic clamping assembly 550 whenthe dynamic clamping assembly 550 is in its proximal most or startingposition. In accordance with another aspect, as was described above, thedynamic clamping assembly 550 includes a vertically extending bodyportion 552 and has an anvil engagement feature 556 that comprises ananvil engagement tab or flange 557 that extends from each lateral sideof the body portion 552. In addition, the dynamic clamping assembly 550includes a channel engagement feature 558 that comprises a channelengagement tab or flange 559 that extends laterally from each lateralside of the body portion 552. As used in this context, the term “flange”connotes a planar feature that extends transversely or perpendicularlyfrom the body portion 552. As such, when viewed from an end, the dynamicclamping assembly 550 resembles an I-beam configuration and may bereferred to herein as a dynamic I-beam clamping member. As can be seenin FIG. 33, a portion of the channel engagement flanges 559 extendproximal of the pin 638 that pivotally couples the cartridge assembly701 to the anvil assembly 612 and which defines a jaw pivot axis JAabout which the anvil and channel may move between open and closedpositions. In addition, although not viewable in FIG. 33, in at leastone arrangement, a portion of each of the anvil engagement flanges 557also extends proximal to the jaw pivot axis JA when the dynamic I-beamclamping assembly 550 is in the parking or starting position. Thisdistance is labeled as distance “PDD₄” in FIG. 33, for example.

A lower end of the body portion 552 of the dynamic I-beam clampingassembly 550 extends through an elongate slot (not shown) in the channel1720. A first lower surface 1726 is formed on a proximal end 1725 of thechannel 1720 on each side of the elongate slot. Each first lower surface1726 terminates distally in a second closure cam surface or ramp 1727that corresponds to each channel engagement flange 559 on the dynamicI-beam clamping assembly 550. When the channel engagement flanges 559engage their corresponding second closure cam surface 1727, thecartridge assembly and the anvil assembly 612 start to close or pivottoward each other by virtue of the interaction of the anvil engagementflanges with corresponding surfaces on the anvil plate and the cammingaction of the channel engagement tabs with the corresponding secondclosure cam surfaces 1727 on the channel 1720. Once the dynamic I-beamclamping assembly 550 has moved distally to a point wherein the channelengagement flanges 559 disengage the second closure cam surfaces 1727,the channel engagement flanges 559 engage corresponding third closuresurfaces 1728 on the bottom of the channel 1720 to keep the anvilassembly and cartridge assembly closed and resist deflection throughoutthe firing process (i.e., as the dynamic I-beam clamping assembly isdistally advanced through the cartridge assembly 701).

In the illustrated arrangement, when the dynamic I-beam clampingassembly 550 is in the proximal most or starting position, the channelengagement flanges 559 are proximal to the second closure cam surfaces1727 yet are in contact with the first lower surface 1726 to limit orotherwise restrict the jaws (anvil assembly 612, cartridge assembly 701)to that amount of jaw aperture represented as angle Θ₁ between a stapleforming surface 625 on the anvil plate 620 and the tissue contactsurface 708 of the cartridge body 702). In the illustrated arrangement,for example, the dynamic I-beam clamping assembly 550 may have to movedistally a distance X from the starting position until the channelengagement flanges 559 start to cammingly engage the second closure camsurfaces 1727 to commence the jaw closure process. In that arrangement,the actuation sled 1712 has a length SL and the cartridge body 702 has anose portion 718 that has a length NL that extends beyond the distal endof the channel 1720.

In accordance with another general aspect, FIG. 34 illustrates anotherend effector 1500′ that includes a parking or docking area 730′ for thedynamic clamping assembly 550 when the dynamic clamping assembly 550 isin its proximal most or starting position. A first lower surface 1726′is formed on a proximal end 1725 of the channel 1720′ on each side ofthe elongate slot. Each first lower surface 1726′ terminates distally ina second closure cam surface or ramp 1727′ that corresponds to eachchannel engagement flange 559 on the dynamic I-beam clamping assembly550. When the channel engagement flanges 559 cammingly engage theircorresponding second closure cam surface 1727′, the cartridge assembly701 and the anvil assembly 612 start to close or pivot toward each otherby virtue of the interaction of the anvil engagement flanges 557 withcorresponding surfaces on the anvil plate 620 and the camming action ofthe channel engagement flanges 559 with the corresponding second closurecam surfaces 1727′ on the channel 1720′. Once the dynamic I-beamclamping assembly 550 has moved distally to a point wherein the channelengagement flanges 559 disengage the second closure cam surfaces 1727′,the channel engagement flanges 559 engage corresponding third closuresurfaces 1728′ on the bottom of the channel 1720 to keep the anvilassembly and cartridge assembly closed throughout the firing process(i.e., as the dynamic I-beam clamping assembly is distally advancedthrough the cartridge assembly 701′ to its ending position).

In the illustrated arrangement, when the dynamic I-beam clampingassembly 550 is in the proximal most or starting position, the channelengagement tabs 559 are located in abutting engagement with the secondclosure cam surfaces 1727′ and are not spaced therefrom. Thus, when thedynamic I-beam clamping assembly is actuated to move distally, thechannel engagement flanges 559 immediately start to cam the cartridgeassembly 701′ closed. Such arrangement provides a jaw aperture angle Θ₂that is greater than Θ₁, for example. Thus, unlike the second jaw 700described above, the dynamic I-beam clamping assembly 550 does not movedistally any distance before it begins to cam the second jaw 700′closed. In that arrangement, the actuation sled 1712′ has a length SL′and a nose portion 718′ that has a length NL′ that extends beyond thedistal end of the channel 1720′. When compared to the above describedarrangement, SL′<SL and NL′<NL, which generally leads to improvedmaneuverability of the end effector 1500′. In other arrangements, thereis at least a portion of the I-beam clamping assembly distal advancementwherein the I-beam clamping assembly is not in contact with both jawsbefore it enters its closure strike portion wherein it begins to opposethe jaws toward one another.

EXAMPLES Example 1

An end effector for use with a surgical instrument. In at least oneexample, the end effector comprises a cartridge assembly that defines alongitudinal axis that extends between a proximal end and a distal endthereof. The cartridge assembly has first and second closure camsurfaces thereon. An anvil assembly is pivotally coupled to thecartridge assembly about a pivot axis that is transverse to thelongitudinal axis such that the cartridge assembly and the anvilassembly are movable relative to each other between a fully open and afully closed position. The end effector further comprises a dynamicI-beam clamping assembly that comprises a body portion that has at leastone anvil engagement feature and at least one cartridge engagementfeature protruding therefrom. The dynamic I-beam clamping assembly isselectively movable between a starting position that corresponds to thefully open position wherein at least a portion of the at least onecartridge engagement feature is proximal to the pivot axis and an endingposition relative to the anvil assembly such that when the dynamicI-beam assembly is moved distally from the starting position, the atleast one cartridge engagement feature cammingly interacts with thefirst closure cam surface to impart a closure motion to the cartridgeassembly to move the cartridge assembly and the anvil assembly to thefully closed position and then engage the second closure cam surface toretain the cartridge assembly in the fully closed position until thedynamic I-beam assembly has been moved to the ending position.

Example 2

The end effector of Example 1, wherein the at least one cartridgeengagement feature is in contact with the first closure cam surface whenthe dynamic I-beam clamping assembly is in the starting position.

Example 3

The end effector of Examples 1 or 2, wherein the at least one cartridgeengagement feature imparts the closure motion to the cartridge assemblyimmediately upon distal advancement of the dynamic I-beam clampingassembly from the starting position.

Example 4

The end effector of Examples 1, 2 or 3, wherein the first closure camsurface is sloped relative to the second closure cam surface.

Example 5

The end effector of Examples 1, 2, 3 or 4, wherein the at least onecartridge engagement feature comprises a planar flange that extendslaterally from the body portion.

Example 6

The end effector of Examples 1, 2, 3, 4 or 5, wherein a portion of eachcartridge engagement feature is not in engagement with the cartridgeassembly when the dynamic I-beam clamping assembly is in the startingposition.

Example 7

The end effector of Examples 1, 2, 3, 4, 5 or 6, wherein the dynamicI-beam clamping assembly comprises a tissue cutting surface.

Example 8

The end effector of Examples 1, 2, 3, 4, 5, 6 or 7, wherein thecartridge assembly comprises a channel that is pivotally coupled to theanvil assembly and defines the first and second closure cam surfaces. Asurgical staple cartridge is operably supported within the channel.

Example 9

The end effector of Example 8, wherein the surgical staple cartridge isremovably attachable to the channel.

Example 10

A surgical loading unit that comprises a housing assembly that has atool assembly operably coupled thereto. The tool assembly comprises acartridge assembly that defines a longitudinal axis that extends betweena proximal end and a distal end thereof. The cartridge assembly hasfirst and second closure cam surfaces thereon. An anvil assembly ispivotally coupled to the cartridge assembly about a pivot axis that istransverse to the longitudinal axis such that the anvil assembly and thecartridge assembly are movable relative to each other between a fullyopen and a fully closed position. The tool assembly further comprises adynamic I-beam clamping assembly that comprises a body portion that hasat least one anvil engagement feature and at least one cartridgeengagement feature protruding therefrom. The dynamic I-beam clampingassembly is selectively movable between a starting positioncorresponding to the fully open position wherein at least a portion ofthe at least one cartridge engagement feature is proximal to the pivotaxis and an ending position relative to the anvil assembly such thatwhen the dynamic I-beam assembly is moved distally from the startingposition, the at least one cartridge engagement feature camminglyinteracts with the first closure cam surface to impart a closure motionto the cartridge assembly to move the cartridge assembly and the anvilassembly to the fully closed position and then engage the second closurecam surface to retain the cartridge assembly in the fully closedposition until the dynamic I-beam assembly has been moved to the endingposition.

Example 11 The surgical loading unit of Example 10, wherein the toolassembly is pivotally coupled to the housing assembly for selectivepivotal travel relative thereto. Example 12

The surgical loading unit of Examples 10 or 11, wherein at least onecartridge engagement feature is in contact with the first closure camsurface when the dynamic I-beam clamping assembly is in the startingposition.

Example 13

The surgical loading unit of Examples 10, 11 or 12, wherein the at leastone cartridge engagement feature imparts the closure motion to thecartridge assembly immediately upon distal advancement of the dynamicI-beam clamping assembly from the starting position.

Example 14

The surgical loading unit of Examples 10, 11, 12 or 13, wherein thefirst closure cam surface is sloped relative to the second closure camsurface.

Example 15

The surgical loading unit of Examples 10, 11, 12, 13 or 14, wherein theat least one cartridge engagement feature comprises a planar flange thatextends laterally from the body portion.

Example 16

The surgical loading unit of Examples 10, 11, 12, 13, 14 or 15, whereinthe dynamic I-beam clamping assembly comprises a tissue cutting surface.

Example 17

The surgical loading unit of Examples 10, 11, 12, 13, 14, 15 or 16,wherein the cartridge assembly comprises a channel that is pivotallycoupled to the anvil assembly and defines the first and second closurecam surfaces. A surgical staple cartridge is operably supported withinthe channel.

Example 18

The surgical loading unit of Example 17, wherein the surgical staplecartridge is removably attachable to the channel.

Many of the surgical instrument systems described herein are motivatedby an electric motor; however, the surgical instrument systems describedherein can be motivated in any suitable manner. In various instances,the surgical instrument systems described herein can be motivated by amanually-operated trigger, for example. In certain instances, the motorsdisclosed herein may comprise a portion or portions of a roboticallycontrolled system. Moreover, any of the end effectors and/or toolassemblies disclosed herein can be utilized with a robotic surgicalinstrument system. U.S. patent application Ser. No. 13/118,241, entitledSURGICAL STAPLING INSTRUMENTS WITH ROTATABLE STAPLE DEPLOYMENTARRANGEMENTS, now U.S. Pat. No. 9,072,535, for example, disclosesseveral examples of a robotic surgical instrument system in greaterdetail.

The surgical instrument systems described herein have been described inconnection with the deployment and deformation of staples; however, theembodiments described herein are not so limited. Various embodiments areenvisioned which deploy fasteners other than staples, such as clamps ortacks, for example. Moreover, various embodiments are envisioned whichutilize any suitable means for sealing tissue. For instance, an endeffector in accordance with various embodiments can comprise electrodesconfigured to heat and seal the tissue. Also, for instance, an endeffector in accordance with certain embodiments can apply vibrationalenergy to seal the tissue.

Although various devices have been described herein in connection withcertain embodiments, modifications and variations to those embodimentsmay be implemented. Particular features, structures, or characteristicsmay be combined in any suitable manner in one or more embodiments. Thus,the particular features, structures, or characteristics illustrated ordescribed in connection with one embodiment may be combined in whole orin part, with the features, structures or characteristics of one oremore other embodiments without limitation. Also, where materials aredisclosed for certain components, other materials may be used.Furthermore, according to various embodiments, a single component may bereplaced by multiple components, and multiple components may be replacedby a single component, to perform a given function or functions. Theforegoing description and following claims are intended to cover allsuch modification and variations.

The devices disclosed herein can be designed to be disposed of after asingle use, or they can be designed to be used multiple times. In eithercase, however, a device can be reconditioned for reuse after at leastone use. Reconditioning can include any combination of the stepsincluding, but not limited to, the disassembly of the device, followedby cleaning or replacement of particular pieces of the device, andsubsequent reassembly of the device. In particular, a reconditioningfacility and/or surgical team can disassemble a device and, aftercleaning and/or replacing particular parts of the device, the device canbe reassembled for subsequent use. Those skilled in the art willappreciate that reconditioning of a device can utilize a variety oftechniques for disassembly, cleaning/replacement, and reassembly. Use ofsuch techniques, and the resulting reconditioned device, are all withinthe scope of the present application.

The devices disclosed herein may be processed before surgery. First, anew or used instrument may be obtained and, when necessary, cleaned. Theinstrument may then be sterilized. In one sterilization technique, theinstrument is placed in a closed and sealed container, such as a plasticor TYVEK bag. The container and instrument may then be placed in a fieldof radiation that can penetrate the container, such as gamma radiation,x-rays, and/or high-energy electrons. The radiation may kill bacteria onthe instrument and in the container. The sterilized instrument may thenbe stored in the sterile container. The sealed container may keep theinstrument sterile until it is opened in a medical facility. A devicemay also be sterilized using any other technique known in the art,including but not limited to beta radiation, gamma radiation, ethyleneoxide, plasma peroxide, and/or steam.

While this invention has been described as having exemplary designs, thepresent invention may be further modified within the spirit and scope ofthe disclosure. This application is therefore intended to cover anyvariations, uses, or adaptations of the invention using its generalprinciples.

What is claimed is:
 1. An end effector for use with a surgicalinstrument, comprising: a cartridge assembly defining a longitudinalaxis between a proximal end and a distal end thereof, said cartridgeassembly comprising first and second closure cam surfaces thereon; ananvil assembly pivotally coupled to said cartridge assembly about apivot axis that is transverse to said longitudinal axis such that saidcartridge assembly and said anvil assembly are movable relative to eachother between a fully open and a fully closed position; a dynamic I-beamclamping assembly comprising: a body portion; at least one anvilengagement feature protruding from said body portion; and at least onecartridge engagement feature protruding from said body portion andwherein said dynamic I-beam clamping assembly is selectively movablebetween a starting position corresponding to said fully open positionwherein at least a portion of said at least one cartridge engagementfeature is proximal to said pivot axis and an ending position relativeto said anvil assembly such that when said dynamic I-beam assembly ismoved distally from said starting position, said at least one cartridgeengagement feature cammingly interacts with said first closure camsurface to impart a closure motion to said cartridge assembly and movesaid cartridge assembly and said anvil assembly to said fully closedposition and then engage said second closure cam surface to retain saidcartridge assembly in said fully closed position until said dynamicI-beam assembly has been moved to said ending position.
 2. The endeffector of claim 1, wherein said at least one cartridge engagementfeature is in contact with said first closure cam surface when saiddynamic I-beam clamping assembly is in said starting position.
 3. Theend effector of claim 1, wherein said at least one cartridge engagementfeature imparts said closure motion to said cartridge assemblyimmediately upon distal advancement of said dynamic I-beam clampingassembly from said starting position.
 4. The end effector of claim 1,wherein said first closure cam surface is sloped relative to said secondclosure cam surface.
 5. The end effector of claim 1, wherein said atleast one cartridge engagement feature comprises a planar flangeextending laterally from said body portion.
 6. The end effector of claim1, wherein a portion of each said cartridge engagement feature is not inengagement with said cartridge assembly when said dynamic I-beamclamping assembly is in said starting position.
 7. The end effector ofclaim 1, wherein said dynamic I-beam clamping assembly comprises atissue cutting surface.
 8. The end effector of claim 1, wherein saidcartridge assembly comprises: a channel pivotally coupled to said anvilassembly and defining said first and second closure cam surfaces; and asurgical staple cartridge operably supported by said channel.
 9. The endeffector of claim 8, wherein said surgical staple cartridge is removablyattachable to said channel.
 10. A surgical loading unit, comprising: ahousing assembly; a tool assembly operably coupled to said housingassembly, said tool assembly comprising: a cartridge assembly defining alongitudinal axis between a proximal end and a distal end thereof, saidcartridge assembly comprising a first and second closure cam surfacesthereon; an anvil assembly pivotally coupled to said cartridge assemblyabout a pivot axis that is transverse to said longitudinal axis suchthat said anvil assembly and said cartridge assembly are movablerelative to each other between a fully open and a fully closed position;a dynamic I-beam clamping assembly comprising: a body portion; at leastone anvil engagement feature protruding from said body portion; and atleast one cartridge engagement feature protruding from said body portionand wherein said dynamic I-beam clamping assembly is selectively movablebetween a starting position corresponding to said fully open positionwherein at least a portion of said at least one cartridge engagementfeature is proximal to said pivot axis and an ending position relativeto said anvil assembly such that when said dynamic I-beam assembly ismoved distally from said starting position, said at least one cartridgeengagement feature cammingly interacts with said first closure camsurface to impart a closure motion to said cartridge assembly and movesaid cartridge assembly and said anvil assembly to said fully closedposition and then engage said second closure cam surface to retain saidcartridge assembly in said fully closed position until said dynamicI-beam assembly has been moved to said ending position.
 11. The surgicalloading unit of claim 10, wherein said tool assembly is pivotallycoupled to said housing assembly for selective pivotal travel relativethereto.
 12. The surgical loading unit of claim 10, wherein said atleast one cartridge engagement feature is in contact with said firstclosure cam surface when said dynamic I-beam clamping assembly is insaid starting position.
 13. The surgical loading unit of claim 10,wherein said at least one cartridge engagement feature imparts saidclosure motion to said cartridge assembly immediately upon distaladvancement of said dynamic I-beam clamping assembly from said startingposition.
 14. The surgical loading unit of claim 10, wherein said firstclosure cam surface is sloped relative to said second closure camsurface.
 15. The surgical loading unit of claim 10, wherein said atleast one cartridge engagement feature comprises a planar flangeextending laterally from said body portion.
 16. The surgical loadingunit of claim 10, wherein said dynamic I-beam clamping assemblycomprises a tissue cutting surface.
 17. The surgical loading unit ofclaim 10, wherein said cartridge assembly comprises: a channel pivotallycoupled to said anvil assembly and defining said first and secondclosure cam surfaces; and a surgical staple cartridge operably supportedwithin said channel.
 18. The surgical loading unit of claim 17, whereinsaid surgical staple cartridge is removably attachable to said channel.